1. Field of the Invention
The present invention relates to a laminated heat exchanger that is used for automotive air conditioning systems, in particular to a laminated heat exchanger which is structured by laminating a plurality of heat exchanging elements, each of which is provided with a pair of tanks that communicate with each other through a U-shaped passage, together with a plurality of corrugated fins.
2. Description of the Related Art
In recent years, depending upon the layout of the engine compartment of the vehicle, it is often the case that positioning the entry pipe or the expansion valve at the tank in the lower section of a heat exchanger creates a hindrance. To deal with this problem, the entry pipe is not normally led out at the end plate side of the heat exchanger. Instead it is led out at the front of the heat exchanger and the piping is disposed at a specific height by leading the pipe around.
However, with this method, the problem of reduced cooling capacity is likely to arise, as the ventilating resistance is increased by the entry pipe, the expansion valve which is connected to the entry pipe, and the like. In order to eliminate this problem, the heat exchanger disclosed in Japanese Patent Unexamined Publication 3-170755 has an entry pipe located on the surface on the side.
This example makes it possible to provide an entry pipe on one side by forming a central tank group or a pipe between a pair of tanks when structuring a coolant path with four or more routes.
However, in the example described above, since the pitch of the entrance to the expansion valve and the pitch of the heat exchanger entrance do not match, a space for mounting the expansion valve is required. Also, as it is necessary to maneuver the entry pipe to this space, no space saving can be realized. Another problem is that the number of components increases.